Normal EEG

Question 1

Describe rhythmic mid temporal theta of drowsiness and its occurrence (RMTD)

Answer 1

• Sharply contoured trains of 4-7hz theta activity
• Temporal and central location
• Notched look
• Occurs in a state of drowsiness or relaxed wakefulness

Question 2

Describe POSTS

Positive Occipital Sharp Transients of Sleep

Answer 2

Positive 4-5 hz theta waves in the occipital regions

occurs in stages 1 and 11 of sleep

Question 3

Describe Lamda and its occurrence

Answer 3

Positive 4-6 hz theta waves in the occipital regions

occurs in the wake state with EO with visual input such as reading, scanning an image

Question 4

Describe the third rhythm (temporal alpha rhythm) and its occurrence

Answer 4

Alpha range activity located in the temporal regions

occurs in wave state

Seen only in some pts with skull defect

Question 5

Describe Mu and its occurrence

Answer 5

• Negative arch shaped
• 7-11hz, located in c3/c4
• can occur unilaterall or bilaterally
• often shifting side to side
• does not attenuate with EO
• Occurs in wake state
• attenuated by having pt make fist with contralateral hand

Question 6

Describe benign sporadic sleep spikes

-also called small sharp spikes (SSS) and benign epileptiform transients of sleep (BETS)- and their occurrence

Answer 6

Low voltage sharp waves that occur on one or both sides in the temporal and frontal regions.

• may mimic EKG artifact
• seen often in referential montage
• occurs in a stage 1-2 sleep

Question 7

Describe subclinical rhythmic electrographic discharge of adults (SRDA) and its occurrence

Answer 7

Periodic sharp activity most often in parietal regions that progresses into a rhythmic theta pattern usually @ 5-7 hz

-occurs in waking state of older Pts

Question 8

Name 3 characteristics that define and describe EEG waveforms

Answer 8

1. amplitude
2. frequency
3. location

Question 9

Describe phantom spike and wave and its occurrence

6hz spike and wave

Answer 9

Posterior or midparietal low voltage spike and wave or in brief bursts

occurs with drowsiness

Question 10

State the frequencies of normal EEG patterns

Answer 10

Beta- greater than 13 hz
Alpha- 8-13hz
Theta- 3.5-7.5 hz
Delta-3hz or less

Question 11

Describe fast alpha variant and its occurrence

Answer 11

• 16-20hz posterior rhythm
• can be 2x pts alpha
• occurs awake with EC
• Attenuates with EO

Question 12

Describe 14 and 6 positive spikes and their occurrence

Answer 12

Sharply contoured trains of 14 & 6 hz spike waves in the posterior region maximal @ t5(p7) and t6 (P8)

• Best seen in contra ear reference
• occur in a state of drowsiness or stage 1 sleep

Question 13

Describe Wicket Spikes and their occurrence

Answer 13

Sharply contoured waves located in the temporal regions

• seen bilaterally or independently
• no slow wave following
• occur in drowsiness or stage 1 sleep

Question 14

Describe slow alpha variant and its occurrence

Answer 14

• A sub harmonic of posterior dominant alpha rhythm often noticed and occurring @ 4.5-5 hz
• occurs in wake state with EC
• Attenuates with EO